Russ Tamblyn, actor (Riff)

I first saw West Side Story on stage in 1958. I was in the army, having been conscripted while under contract to MGM. I caught the musical in New York, fell in love with it, bought the album, and memorised the whole thing. I wanted to be Tony, the Romeo character, so I learned all his songs.

When I came home from the army, the film part came up. But it wasn't with MGM – it was with United Artists. They wanted me to test for Tony and MGM allowed it. Later, I was told they'd narrowed it down to me and one other. Riff was never mentioned. I was pretty sure I didn't want that role, because my dancing wasn't great. But then my agent called and said: "Well, Richard Beymer got Tony, but you can be Riff." If you watch the film, you'll see I strut a lot because I never had any dance training.

There was still a problem: MGM. I went to see the studio director and he said: "I'm sorry, but these are some of the lines you'd have to say, 'My sister wears a moustache/ My brother wears a dress/ Goodness gracious, that's why I'm a mess!'" He quoted all these other great lyrics from the Gee Officer Krupke section and then said: "You've got a reputation to keep, so we've booked you on another movie." Eventually, I convinced them to let me do it.

Beymer wasn't happy with his performance as Tony. He thought he was miscast: he was from a farm in Indiana and had no street sense whatsoever. He needed a lot of direction and didn't get it; they just stuck fake teeth in his mouth instead. The other thing that upset him was that Natalie Wood despised him. She had a "shit list" on her dressing room wall – and Richard's name was top. I asked her why her Romeo was on it and she said: "I just don't like him."

The director Jerome Robbins asked the gangs to keep totally separate. There was never any animosity, but we used to play pranks on each other. After I sing When You're a Jet, I tell Bernardo "Beat it!" with real venom. So Michael Jackson stole that from me. How about that!

George Chakiris, actor (Bernardo)

I'd been playing Riff in the London stage show for over a year when the movie was announced. They were floating names like Elvis Presley, Elizabeth Taylor, Warren Beatty and Robert Redford. So none of us thought in our wildest dreams we'd be cast.

Then five of us were invited to do a test scene, so we stole our stage costumes and went to Elstree for the day. Weeks went by and then I got a call from Robbins, who asked me out to LA. They wanted me to be Bernardo. I concluded that the Sharks parts had more meat: we sang America and had more scenes with Natalie, who plays Bernardo's sister Maria, based on Juliet. None of us put on very heavy Puerto Rican accents. The danger in going too strong is that it will show up the cracks. Rita Moreno, who played Anita, is Puerto Rican, so we all turned to her if we had trouble pronouncing our lines.

There was great camaraderie. One day, one of the Sharks went to a sports store and bought a leather archer's wristband. We all ended up buying one and the costume designer liked them so much we got to wear them in the film.

I was asked to take 10 weeks' leave to make the film, which turned into seven months. Others had been rehearsing long before that, so the project lasted over a year. But we loved it; we played, we laughed, and we always felt we were working on something of quality.